The present invention relates generally to hand-held electric saws. More particularly, the present invention relates to base clamping systems for jigsaws having pivoting bases.
Electrically powered jigsaws, also known as saber saws, are well known in the art. A principle advantage of jigsaws over other types of hand-held saws such as circular saws or band-type saws is the ability to make curved cuts along relatively short radiuses. Consequently, jigsaws are particularly useful in performing tight scrolling cuts to cut curves into a work piece.
A conventional jigsaw typically includes an electric motor contained within a housing, and a shoe positioned beneath the housing. The shoe includes a bottom surface adapted to slide or ride along the top surface of a work piece. An open-ended slot is formed at a front end of the shoe. A straight, bayonet-type saw blade extends downward from the housing through the front slot. A leading edge of the blade includes a plurality of teeth that face in a forward direction toward the front of the shoe. In use, the blade is reciprocated in a generally up-and-down direction by the motor. As the blade is reciprocated, the jigsaw is manually advanced in a forward direction such that the teeth of the blade cut into a work piece. As the blade cuts into the work piece, the bottom surface of the shoe rides over the top of the work piece.
Some jigsaws are capable of producing an orbital blade motion. Such a motion has a rectilinear component of a generally up-and-down nature, and fore-and-aft motion advancing the cutting blade into the work piece. Typically, the blade advances on the cutting stroke, which is conventionally in the upstroke on most saws.
Commonly, jigsaws are used to provide perpendicular cuts through a work piece. However, frequently, a user may desire to provide a bevel cut through a work piece. A bevel cut is a cut at an angle other than perpendicular such as angles that are offset 15xc2x0, 30xc2x0 or 45xc2x0 with respect to perpendicular. To achieve a bevel cut with a conventional jigsaw, the motor housing and the blade are pivoted relative to the jigsaw shoe. Specifically, the housing is pivoted about a front-to-rear longitudinal axis. By pivoting the housing relative to the shoe, the blade can be aligned at a desired oblique angle relative to the bottom surface of the shoe. Typically, the housing is retained in the desired orientation relative to the shoe by a clamp mechanism. When the clamp mechanism is tightened, relative movement between the housing and the shoe is inhibited. When the clamp mechanism is loosened, the housing and the shoe can be pivoted relative to one another. It is desirable for the clamping mechanism to be easy to operate. It is also desirable for the clamping mechanism to effectively hold the shoe in the desired orientation without undesired loosening.
One aspect of the present invention relates to a jig saw including a base structure, and a housing pivotally moveable relative to the base structure about a first axis that extends longitudinally along the base structure. A motor is positioned within the housing. The motor reciprocates a blade in an up and down motion. A connecting member extends between the housing and the base structure. The saw also includes a first wedge that cooperates with the connecting member to clamp the housing relative to the base structure. The first wedge is moveable to a first position in which the connecting member is caused to compress the housing and the base structure together such that pivotal movement between the housing and the base structure is inhibited. The first wedge is also moveable to a second position in which the housing can be manually pivoted relative to the base.
Another aspect of the present invention relates to a jig saw including a housing pivotally mounted on a base. The housing and base are connected by a connecting member that extends through a transverse pivot slot defined by at least one of the housing and the base. A motor for reciprocating a blade is mounted within the housing. The saw also includes first and second wedges. The first wedge is moveable relative to the connecting member, while the second wedge is mounted on the connecting member. The housing is clamped in a desired pivotal position relative to the base structure by moving the first wedge toward the second wedge such that contact between ramp surfaces of the wedges causes the connecting member to compress the housing and the base structure together.
A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.